alexa Stress-related transcription factor AtfB integrates secondary metabolism with oxidative stress response in aspergilli.
Genetics & Molecular Biology

Genetics & Molecular Biology

Fungal Genomics & Biology

Author(s): Roze LV, Chanda A, Wee J, Awad D, Linz JE

Abstract Share this page

Abstract In filamentous fungi, several lines of experimental evidence indicate that secondary metabolism is triggered by oxidative stress; however, the functional and molecular mechanisms that mediate this association are unclear. The basic leucine zipper (bZIP) transcription factor AtfB, a member of the bZIP/CREB family, helps regulate conidial tolerance to oxidative stress. In this work, we investigated the role of AtfB in the connection between oxidative stress response and secondary metabolism in the filamentous fungus Aspergillus parasiticus. This well characterized model organism synthesizes the secondary metabolite and carcinogen aflatoxin. Chromatin immunoprecipitation with specific anti-AtfB demonstrated AtfB binding at promoters of seven genes in the aflatoxin gene cluster that carry CREs. Promoters lacking CREs did not show AtfB binding. The binding of AtfB to the promoters occurred under aflatoxin-inducing but not under aflatoxin-noninducing conditions and correlated with activation of transcription of the aflatoxin genes. Deletion of veA, a global regulator of secondary metabolism and development, nearly eliminated this binding. Electrophoretic mobility shift analysis demonstrated that AtfB binds to the nor-1 (an early aflatoxin gene) promoter at a composite regulatory element that consists of highly similar, adjacent CRE1 and AP-1-like binding sites. The five nucleotides immediately upstream from CRE1, AGCC(G/C), are highly conserved in five aflatoxin promoters that demonstrate AtfB binding. We propose that AtfB is a key player in the regulatory circuit that integrates secondary metabolism and cellular response to oxidative stress.
This article was published in J Biol Chem and referenced in Fungal Genomics & Biology

Relevant Expert PPTs

Relevant Speaker PPTs

Recommended Conferences

  • World Congress on Mycology
    September 11-13, 2017 Los Angeles, USA
  • International Conference on Microbial Ecology
    September 18-20, 2017 Toronto, Canada
  • International Conference on Fungal Diseases & Control
    September 25-26, 2017 Dubai, UAE
  • 2nd International Conference on Mycology & Mushrooms
    September 25-26, 2017 Chicago, USA

Relevant Topics

Peer Reviewed Journals
 
Make the best use of Scientific Research and information from our 700 + peer reviewed, Open Access Journals
International Conferences 2017-18
 
Meet Inspiring Speakers and Experts at our 3000+ Global Annual Meetings

Contact Us

 
© 2008-2017 OMICS International - Open Access Publisher. Best viewed in Mozilla Firefox | Google Chrome | Above IE 7.0 version
adwords